Different designs have been offered for expandable liner hangers. In one design a pattern of grooves with a sealing material are placed on the outer surface of the hanger. Surrounded by the groove are carbide segments that are fabricated into the tubular body or are buttons with teeth or using raised or serrated members on the outer surface of the tubular or hardened tooth patterns on the outer surface. Such designs are illustrated in U.S. Pat. No. 6,688,399 and U.S. Pat. No. 6,691,789. A similar design illustrating hardened inserts retained in pockets on the outer surface of a tubular are shown in U.S. Pat. No. 8,443,881. U.S. Pat. No. 6,098,717 illustrates an expandable liner hanger with a seal in some embodiments.
These designs are expensive to fabricate the complex pattern of grooves and the application of the seal material that fits in the grooves. The manner of applying the carbide was also prone to dislodge the particles.
Another design uses a series of rubber sleeves to seal and support the liner weight as indicated in U.S. Pat. No. 8,371,388. The use of rubber for both these functions requires many rings and long tool length with a resulting difficulty in running in in certain applications with limited weight capacity.
What is needed and provided by the present invention is a way to apply the hardened material or carbide so that it will stay put for run as well as during expansion. The mounting method involves taking uncured rubber into a slurry form with a fluid such as methyl ethyl ketone (MEK) and applying the slurry to the liner hanger body directly or to a support that is subsequently fitted on the hanger body. A bonding agent or adhesive is applied to the hardened particles or carbide and allowed to dry before adding such particles to the rubber slurry. The combination of the rubber slurry and carbide particles is autoclaved in an oven to vulcanize the rubber. In use the rubber retains the carbide during expansion and allows the load to be transferred from the supported string through the carbide to the expanded mandrel. The assembly of carbide retained with the vulcanized rubber can be placed directly in a recess for protection against abrasion during running in. Alternatively, the assembly can be mounted to a support ring that can be disposed in a recess on the mandrel outer wall. Those skilled in the art will better appreciate additional aspects of the invention from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be determined from the appended claims.